This invention relates to a filtration process for swimming pools enabling to considerably improve the effectiveness of the filtration by increasing the flow of filtered water without increasing the power of the pumps needed for the water circulation.
Conversely, it is possible, by using pumps of reduced power, to maintain the same filtration quality than obtained with higher-powered pumps.
According to the U.S. Pat. No. 4,501,659, an approach has attempted to use the pump return or discharge flow, i.e. the water returned to the pool after filtration, to increase the suction rate of the water admitted into an added basket acting as what is known as a surface skimmer or xe2x80x9cskimmer.xe2x80x9d This approach, illustrated in particular in FIG. 7 of this patent, and sketched in FIG. 8 of this request, uses the effect known as xe2x80x9cVenturixe2x80x9d to send the pump return flow through a tubing 117 that opens by a nozzle 119 in a port 124 at the base of the receptacle 113 which the pool water enters through an opening 114. The water return from the circulation pump, if it takes place for instance under a flow of 10 m3 will generate, as it drives the water stream, an output flow of 25 m3 for instance as it exits the port 124. These 15 m3 are thus sucked through the opening 114, instead of the 10 m3 only that would be obtained if all the pump return water had to be replenished though the opening 114. Not only is the inflow increase not actually significant, but this device is inconvenient to use because it does not in particular enable to select the best locations for the return and the suction which will necessarily be superimposed. Moreover, this document does not address an actual water filtration, but only the gathering in the basket 134 of the biggest particles such as leaves that may float on the water. FIG. 9 will help to better understand the operating principle of this patent. FIG. 9 shows the diagram of the overall system lay-out, supposing for instance that the water suction is performed by a pump 10, at the level of a bottom plug 11, via a filter 12, with the return in 13 (corresponding to the opening 124 of FIG. 8) and the suction in 14, right above (corresponding to the admission opening 114) for the recycling in that part of the pool of a water stream going through the basket 134.
Contrary to the abovementioned document approach, this invention uses at least some of the return water flow of the circulation pump to send it in at least one flow multiplier, consisting essentially of a convergent tuyere followed by a divergent tuyere with, at the intermediary location, an admission for said pump return water flow, the entrance on the side of said convergent tuyere of the flow multiplier communicating with at least one admission for the water to be filtered that comes from the swimming pool and goes through a filter suitably set upstream from this admission; meanwhile, the exit on the side of the divergent tuyere opens to the return pool.
Not only is the flow multiplier of this invention markedly more effective, as shown more clearly in the following description, than the nozzle driver of the document U.S. Pat. No. 4,501,659, but in addition the process of this invention enables to filter the total multiplied water flow and, besides, to feedback the return water with its multiplied flow to any suitable pool location.
According to another characteristic of this invention, the admission of the water to be filtered can be advantageously performed by means of at least one skimmer.
The invention also relates to a water flow multiplier, characterized in that it consists of:
on the suction side a convergent tuyere;
on the return side a divergent tuyere;
at the neck level, between the two connecting tuyeres, a ring around the narrower section, said ring receiving the pump return water that comes through an annular slit to the beginning of the divergent tuyere.
This invention also relates, of course, to a swimming pool equipped with a filtration system designed according to this process or equipped with a flow multiplier according to this invention.
The invention and its implementation will appear more clearly from the following description in reference to the accompanying drawings.